"PARANOiA" by 180 (alias of Naoki) is one of the two hardest songs from the first Dance Dance Revolution. (RemyWiki; YouTube) But with the overall inflation in boss song difficulty over the course of the DDR series, it's now considered one of the easier songs.

Konami tried to cover it on Game Boy for Dance Dance Revolution GB, but in my opinion they butchered it. (It's telling that despite being the sound producer for DDR 2nd Mix through DDR X, Naoki isn't in DDR GB's credits.)